Foamable molding compositions containing chemical blowing agents are known. U.S. Pat. No. 3,888,801 discloses the chemical blowing agents which are suitable in the context of the present invention. Resins which are suitable in the present invention are also disclosed in that patent.
Polycarbonate compositions having an improved level of impact strength comprising an aromatic polycarbonate, glass fibers and a polyanhydride have been disclosed in U.S. Pat. No. 4,420,584. U.S. Pat. No. 4,207,402 discloses foamable compositions comprising certain addition polymers in combination with an interpolymer of an alkyl aromatic monomer and maleic anhydride and a particular foaming agent. The advantages said to be associated with the invention relates to the attainments of shorter molding cycles.